An audio signal processing apparatus performing audio signal processing in a plurality of signal processing channels in which an audio signal in an arbitrarily selected signal processing channel can be monitored has been conventionally known (refer to NPL1). Functions relating to the monitoring is called as a CUE function or a monitoring function.
In a digital mixer described in NPL1, a user can instruct the digital mixer, by operating a CUE key provided in a channel strip, to output an audio signal in a signal processing channel which corresponds to the channel strip to a CUE bus, and to output the audio signal as a cue signal for monitoring via the CUE bus.